The invention pertains to a method and to an apparatus for controlling the brake system of a vehicle.
A method and an apparatus for controlling a brake system are known from DE 4,112,845 A1. In the compressed-air brake system described there, the application pressure of the individual wheel brakes is determined by evaluation of the change over time in the braking pressures during an actuation of the brakes. The determined application pressure is used to correct the nominal pressure, derived from the driver's command, for the individual wheel brakes in such a way as to produce a braking force which is equal at all the wheels of the vehicle or at all the wheels of one axle. The corresponding measure can also be used to determine the release pressure when the brake is released. It has been found in this case that, when the hystereses (the difference between the pressure upon application and release of the brake) of the wheel brakes are different, the braking forces at the individual wheel brakes or at the brakes of individual component vehicles of a vehicle combination can differ widely at the time of application and at the time of release. This leads to different braking forces at the individual wheel brakes or within the individual component vehicles, which leads in turn to nonuniform wear of the wheel brakes and to longitudinal forces between the component vehicles. It is especially difficult to determine the application and release pressures in the case of trailers or semitrailers for which no information is available concerning the current condition of the wheel brakes.
The task of the invention is to provide measures for determining and suitably compensating the actuating variables for application and/or release (e.g., the application and/or release pressures in the case of compressed-air brake systems) or the application and/or release points of the brakes of a vehicle combination.
This object is achieved by the invention herein.